Calculates the angle atan2 (double y,double x) between the calculated point and the x-axis positive half axis, returning the Radian system (-PI,PI]

The accuracy is higher than ACOs, ASIN what.

Parameters

Y

Value representing the proportion of the y-coordinate.

X

Value representing the proportion of the x-coordinate.

If both arguments passed is zero, a domain error occurs.

So just remove the x=y=0 before use

Example:

/*atan2 Example*/#include<stdio.h>/*printf*/#include<math.h>/*atan2*/#definePI 3.14159265intMain () {Doublex, y, result; X= -10.0; Y=10.0; Result= atan2 (y,x) * the/PI; printf ("The arc tangent for (x=%f, y=%f) is%f degrees\n", x, y, result); return 0;}

Results:

 for (x=-10.000000, y=10.000000is135.000000 degrees.

The return value is an example of (-pi,pi]

printf ("%lf", atan2 (0,-1) *P/PI); output:  180.000000

Calculates the angle atan2 (double y,double x) between the calculated point and the x-axis positive half axis, returning the Radian system (-PI,PI]